1. Field of the Invention
The present invention relates to a silica nanocomposite and a composite foam, methods of preparing the silica nanocomposite and the composite foam.
2. Description of the Related Art
Aerogels are ultrafine porous low density materials. Aerogels have been used in various applications including catalyst carriers, insulating materials, noise shielding materials, and particle accelerators. Silica aerogels are inorganic insulating materials and show thermal insulating effects even at elevated temperatures. In general, silica aerogels prepared using low-temperature supercritical drying have a hydrophilic surface. The use of silica aerogels as thermal insulating materials results in poor insulation because of the adsorption of water molecules to the hydrophilic surface. Therefore, a separate surface treatment process is used to make the surface of silica aerogels hydrophobic. An example of such a silica aerogel is disclosed in U.S. Pat. No. 6,475,561.
In general, a silica aerogel is prepared using a high-temperature and high-pressure supercritical drying method. The silica aerogel obtained using such supercritical drying method is expensive and brittle.